History of Life Flashcards

1
Q

define macroevolution

A

broad pattern of change above a species level

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2
Q

what does macroevol tell us about

A

emergence of terrestrial vertebrates, mass extinctions, origin of flight in birds

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3
Q

when did earth form

A

4.6 bya

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4
Q

did early earth have lots of O2

A

no

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5
Q

process how life originated

A
  1. abiotic synthesis of small organic molecules
  2. joining of smaller mlecules into macromolecules such as proteins and NA
  3. Packaging of macromolecules into protocells(droplets w/ membrane that separated inside protocell from external env)
  4. Origin of self-replicating molecules that eventually made inheritcance possible
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6
Q

what is the fossil record biased towards

A
  1. hard animals
  2. widespread distribution
  3. lived for long
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7
Q

what are the 4 major eons

A

Hadean, Archaean, Protozeric, Phanerozoic

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8
Q

hadean

A

beginning of planet to 4 bya

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9
Q

archaean

A

4 bya to 2.5 bya

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10
Q

proterozoic

A

2.5 bya-.5 bya

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11
Q

phanerozoic

A

.5 bya-present

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12
Q

what eras is the phanerozoic divided into

A

paleozoic, mesozoic, cenozoic

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13
Q

what organisms have dominated life for the majority of time

A

microbes

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14
Q

when did the first single-celled organism form

A

3.5 bya

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15
Q

what were earth’s sole inhabitants for 1.5 by

A

Prokaryotes (bacteria + archaea)

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16
Q

what are the oldest known fossils and when

A

stromatolites(3.6 bya)

17
Q

when did O2 begin accumulating

A

2.7 bya from photosyntehsizing organisms

18
Q

when was the O2 rev

A

2.7-2.3 bya
inc O2 levels by 3-4 orders
some were poisoned by this- many prok went extinct

19
Q

when were the first eukaryotes

A

1.8 bya via endosymbiosis

20
Q

when were the first multicellular euk

A

small algae 1.2 bya

21
Q

larger and more diverse euk(plants, animals, fungi) not in fossil record until….?

A

600 mya

multiellularity evolved independelty

22
Q

cambrian explosion

A

small window of time(10 million)
btwn protozoic and phanerozoic
appearance of fossils resembling modern animals
first evidence of predator prey interactions in fossil record
soft bodies appeared after

23
Q

colonizing land

A
500 mya- fungi, animals, plants on land
420 mya- vascular tissue in plants
365 mya- tetrapods evolved from fish
6-7 mya- origian of human lineage from chimps
200,000 ya- origin of modern humans
24
Q

what has influenced patterns of diversity

A

plate tectonics, mass extinctions, adaptive radiation

25
effects of continental drift on living organism
alters habits in which organisms live, climate on continent could change based on latitude, separation of land masses leads to allopatric speciation
26
fossils and continental drift
distribution of fossils and living groups relfect historic mbmt of continents before 135 mya, fossils shared siilarity in parts of south American and africa.....were formerly attached
27
mass extinctions
vast majority of species ever lived on spanet now extinct(99.9%) caused by change to a species env result of disruptive, global, env change 5 majors ones, each with > 50% marine life going extinct
28
Permean and cretaceous ME
Permian- biggest extinction, 251 mya, btwn paleozoic and mesozoic, volcanism, extinction of 96% oF MArine animals Cretaceous- not as severe, 65 mya, between mesozoic and cenozoic, 50% of marine species went extinct and dinos went extinct, percentage of marine organisms that were predators increased
29
define adaptive radiation
rapid speciation rate for 1 lineage from a common ancestor
30
adaptive radiation
shape distribution of species diversity of organisms lineages w. novel and advantageous features can be lost during mass extinctions ME can pave way for AR usually follows: ME, evol of novel characteristics, and colonization of new regions
31
global AR
mammals had one after dino extinction | other radiations: photosynthetic prok, large predators in cambrian, land plants, flying insects, waking tetrapods
32
regional AR
occupy particular regions, not worldwide organisms colonize new env w/ little comp ex. hawaiian islands drosophila
33
macroevolution allow for what?
study of traits traits and novel traits evolve by tinkering most novel traits/structures evolve in many stages from previously existing structures NS an only improve a structure in context of current utility
34
evolutionary novelties
complex eyes have evolved from simple photosensitive cells independently many times modern day mollusks show eye structure from patch of pigmented cells to complex lens
35
evolutionary trends
extracting a single evol progression from fossil record can be misleading apparent trends should be examined ina broader context does not imply an intrinsic arive toward a specific ptype
36
what are the key events in life's history
origins of unicellular and multicellular organisms and colonization of land
37
diversity patterns of diff groups of organism reflect differences in ?
speciation
38
is evol goal oriented?
NO! but selection is